Topochemical Polymerization: Diynes

Solid-State Metathesis Polycondensation

“…The principles governing these two types of polymerization are quite different, for the former is topological chemistry, while the latter occurs in the amorphous state of semicrystalline polymers. Topological SSP (the polymerization of diacetylenes , and diolefins are examples) relies on a suitable arrangement of the reactants in the monomer crystal to permit the necessary contact between reacting groups with only the slight vibrations allowed within a crystalline state. On the other hand, significant molecular motions occur in polycondensation SSP, mostly in the amorphous phase.…”

“…Key factors in any solid-state polycondensation are the nature and the lifetime of the catalyst employed, in this case, metathesis catalysts. Three of the most widely used metathesis catalysts are bis(tricyclohexylphosphine) benzylidine ruthenium(IV) dichloride (1), 12 13 and 2,6-diisopropylphenylimidoneophylidene molybdenum(VI) bis(hexafluoro-tert-butoxide) (3), 14 commonly known as the first (1) and second (2) generation Grubbs ruthenium catalysts and Schrock's molybdenum catalyst (3), respectively. Thus far, we have shown that the two Grubbs catalysts promote solid-state ADMET polymerization.…”

Distance-Selected Topochemical Dehydro-Diels–Alder Reaction of 1,4-Diphenylbutadiyne toward Crystalline Graphitic Nanoribbons

“…One promising approach to obtain crystalline polymeric structures is solid-state topochemical polymerization (SSTP). The unsaturated molecules are confined in crystal lattices and usually react with a minimum movement; hence, the structure of the product can be predicted and designed from that of the reactant crystal via a crystal-to-crystal route. − The most well-known example is the 1,4-addition polymerization of diacetylenes, which yields conjugated linear en-yne crystals with excellent optical and electrical properties. − Unfortunately, the reaction types of the SSTP are very limited, and only a few monomers like diacetylene, − triacetylene, diene, triene, and olefins can polymerize topochemically through the 1,4-addition or [2 + 2] cycloaddition reaction. New SSTP reactions are still needed to be developed.…”